An issue was discovered in phpMyAdmin. Due to a bug in serialized string parsing, it was possible to bypass the protection offered by PMA_safeUnserialize() function. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.
https://www.phpmyadmin.net/security/PMASA-2016-70
https://security.gentoo.org/glsa/201701-32
https://lists.debian.org/debian-lts-announce/2018/07/msg00006.html